Spark-plug.



H. DAFFRON.

SPABK PLUG. APPLICATION FILED JUNE I. 1918.?

Patented Feb. 25, 1919.

VHTN ESSES Y Y E N H O T T A HEN GEL DAFFRON, 0F DETROIT, MICHIGAN SPARK-PLUG.

To all whom it may concern:

Be it known that I, HENCEL DA'FFRoN, a citizen of the United States, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Spark-Plugs, of which the following is a specification.

This invention relates to internal combustion engines, and more especially to the ignition thereof; and the object of the, same is to produce an improvedspark plug.

The invention consists first in a peculiar means for mounting the porcelain within the bodyof the plug, and second in the peculiar formation of the lower end of the body so that the sparks may drive the carbon laterally out of such body.

Details are set forth in the following specificationand claims, and reference is made to the drawings, wherein Figure 1 is a central vertical section of this improved plug and Fig. 2 is a bottom plan view thereof.

The body is indicated by the numeral 1,v

internally shouldered as at 2 and externally flanged as at 3 about opposite the shoulder. The lower end of thejbody is provided with preferably four notches 4 disposed about as seen in Fig. 2 and one terminal 5 passes out of said'end between two of the notches and turns inward, while the other terminal '6 passes down through the center of the porcelain 7, its upper end 8 having suitable means for attachment of the wire from the ignition system. The return of the current is through the terminal 5 and body 1, and through the flange 3 which is borne down into reliable contact with the cylinder by screwing the plug into an appropriate opening therein, for which'purpose it is threaded as shown at 19, the threads passing down for a considerable distance on the fingers between the several notches.

The porcelain 7 preferably is provided with an exteriorv annular shoulder 17 which is larger than the body of the porcelain and yet of a size to pass into the bore of the body 1; and around the upper end of said porcelain a heading 18 is wise formed so as to protect the porcelain from injury by accidental blows. The upper end of the body 1 is internally threaded as at 11, and a packing nut 12 goes into the same around the porcelain, its lower end Specification of Letters Patent.

welded or other- Patented m. 25, 191-9.

Application filed June 1, 1918. Serial N 0. 237,729.

bearing on the shoulder 17 and therefore pressing the latter and the entire porcelain downward. Beneath said shoulder and above the shoulder 2 in the body are disposed a plurality of washers. The numeral 13 designates the upper washer which is quite thin and of metal such as steel. The

numeral 14 designates the intermediate washer which is preferably of fiber inclosed .within copper and of that type known as the plug is prevented, as well as short-cir cuiting. The employment of a plurality notches 4 through the wall of the body 1 .at its lower end and around the terminals 5 and 6, is what I consider an extremely important feature of my invention. At each upward stroke of the piston the charge is compressed in the head of the cylinder and to an extent within the open lower end of the spark plug, and therefore when the spark occurs the compressed charge is exploded at the spark gap and the explosion itself scatters the flame in all directions. Obviously it finds its most ready exit from the spark plug downward because there is no obstruction in that direction. Also it passes upward around the reduced lower end of the porcelain. But with my invention it passes also outward radiallyin four directions provided there are four of the notches numbered 4, and therefore all parts of the compressed charge in the head of the cylinder around the spark plug are ignited simultaneously. Alsothe scattering of the explosion in this direction drives out of the lower Y may make such arrangement andcombmation of parts, ma-

described that the statements I make are corroborated by thefacts.

The foregoing ings have reference to what maybe considered the preferred, or approved, form of my invention. It is to be understood that changes in'construction and of the body, a flan ed washer resting on the,

shoulder of the ody, a packing washer above the flanged Washer, and a flat washer Copies of this patent may be obtained for description and the drawfive cents each,

above the packing washer beneath the shoulder 0? the porcelain.

2.- n a spark plug, the combinatmn with a tubular body having an internal shoulder, internal threads at its upper end, and

I notches in its lower end; of a porcelain Whose body is smaller than the bore of said metal body and is provided with a shoulder fitting said bore and standing above that of the metal body, terminals respectively carried by the body and the porcelain, a nut screwed into the upper end of the body, a flanged washer resting on the shoulder of the body, a packing washer above the flanged v fiat washer above the packing washer, and a the shoulder on the porcewasher beneath lain.

In testimony whereof I aflix my signature in presence of two witnesses.

HENCEL DAFFRON.

Witnesses:

ROBERT H. DUNCAN,- J. H. MILLS.

by addressing the Commissioner of Patents,

Washington, D. 0. 

